Apparatus for breaking glass



Nov. 17, 1964 D. DE GORTER APPARATUS FOR BREAKING GLASS Original FiledFeb. 16, 1959 I III/I Illllllll AAAAAAA/A I I III OSC.

DANIEL De GORTER BY aTrcm mavrs United States Patent Ofilice EJ575329Patented Nov. 17, 1954 3,157,329 APPARATUS HER BREAKING GLASS Daniel DeGarter, 35 E. 35th St., New York, NE. riginal application Feb. 16, 1%9,Ser. No. 793,417 new Patent No. 3,116,862, dated Jan. '7, 1964. Dividedand this application Apr. 10, 1953, Ser. No. 271,988 9 Claims. (Cl.225-93) This invention relates to a new and novel method of breakingglass and new and novel instruments for carrying out the process.

One of the objects or" the present invention is to provide a new andnovel method of breaking thick sheets of glass wherein the break isclean and along a predeterrnhed path.

Another object is to provide a new and novel method and a new and novelinstrument for breaking any thickness of glass along any desired patternor path.

Another bject is to provide a new and novel method of breaking glassalong a predetermined path by subjecting the surface of the glass alongsaid path to a series of rapid percussion vibrations.

Another object is to provide a new and novel method of breaking glassalong a predetermined path by subjecting the surface of the glass alongsaid path to ultrasonic vibrations.

Another object is to provide a method of breaking thick glass bysimultaneously or sequentially subjecting the surfaces to be broken tohigh frequency and intensity vibrations.

Another object is to provide a new and novel instrument for producing5,000 to 20,000 vibrations per minute and which is adapted to transmitsaid vibrations to a glass surface which is to be broken.

A still further object is to provide a new and novel instrument forproducing ultrasonic vibrations in the range of 16,000 to 160,000vibrations per second and which is adapted to transmit said vibrationsto a surface of the glass to be broken.

Other objects of the invention wil become apparent as the specificationand drawings are studied.

In the drawings wherein like reference characters refer to like partsthroughout the several views,

PEG. 1 is a perspective view of a glass sheet showing scratch lines onthe top and bottom surfaces to define the area along which the sheet isto be broken;

FIG. 2 is a side elevational view, shown partly in crosssection, of oneform of instrument for breaking glass;

FIG. 3 is a side elevational view, shown partly in crosssection, ofanother form of instrument for breaking glass;

FIG. 4 is a cross-sectional view of the instrument for creatingultrasonic vibrations for breaking glass;

FIG. 5 is a cross-sectional View of a modified form of the instrumentshown in PEG. 4 for creating ultrasonic vibrations for breaking glass;and

PEG. 6 is a cross-sectional view of the instrument shown in FIG. 5submerged in a fluid bath.

It is well known that when a deep enough scratch is made on the surfaceof glass a weak zone is created in the structure of the glass and maycause local breakage which, under certain conditions may extend muchbeyond the location of the original scratch. It is on the basis of thisphenomenon that the art of cutting glass has been developed. It is alsowell known that by using a diamond point, or a sharp metal wheel, orsome other hard material, deep cuts can be developed on the surface ofglass so that when the proper strain is applied to the glass areasabutting such cuts the breakage will occur along those cuts. While it iseasy to break pieces of glass having a thickness of or of an inchaccording to the above described method, the problem becomes moredifficult when this method is applied to a piece of glass A inch thickrequiring the scratch to be much deeper. This problem becomesincreasingly more difilcult when applied to pieces of glass having athickness of A or /2 of an inch, the last-mentioned glass thicknessesbeing those most frequently used in the glazing of large openings. Whenthe glass to be cut has a thickness of several inches, or even severalfeet, as is the case of protective glass now being used for openings inatomic plants, the above-do scribed method will not operate. The presentinvention is directed to solving this problem of cutting thick glassalong a predetermined path or pattern. It was found that the best methodof cutting glass of any thickness was to subject the surface of theglass to vibrations of sufficiently high frequency and of suflicientintensity, preferably along the scratch lines made in the usual manner,to cause the glass to break evenly along this scratch line. This methodis even more applicable when it is desired to cut a complicated patternextending from one edge of the sheet to the other or when the area to becut comprises a closed pattern contained within the edges of the glasssheet.

Referring now to the drawings, there is shown a suitable instrumentembodying the present invention which is particularly adapted for thecutting of complicated glass patterns or glass up to /2 of an inch inthickness. FIG. 2 shows an instrument having a cylinder 10 and afloating piston 11 mounted therein. A plurality of lugs 12 arecircumferentially spaced about the lower inner surface of cylinder 10and serve as a stop for piston ll. Ports l3 and 14 open into the top andbottom or" the cylinder, respectively, and on either side of thefloating piston. These ports are operatively connected to separatesources of fluid pressure which are not shown. The sources of fluidpressure alternately operate at a rapid rate to cause the piston tooscillate within the cylinder at a high speed. When the piston is forceddownwardly during the injection of lluid through port 33 it strikes thelugs 12 and causes entire cylinder to vibrate. A downwardly dependingarm 15 having a hardened point 16 such as a diamond, or a hardened metalpoint or wheel at one end is securely fastened at its other end to thelower surface of the cylinder. Consequently, as the piston repeatedlystrikes the lugs 12 vibrations are set up in the cylinder which are inturn transmitted to the arm 15 and the hard point in. By controlling thespeed of the alternate feeding of fluid pressure the hard point of theinstrument can vibrate in the range of about 5,000 to 20,000 vibrationsper minute. There is shown in FIG. 3 a modification of the instrumentshown in FIG. 2 wherein the fluid pressure source and ports are replacedby an electromagnet 17 which is connected with a source of oscillatingcurrent, not shown, to cause the piston ll to rapidly move up and downin its cylinder. Vibrations within the range of 5,000 to 20,000vibrations per minute can be realized on this instrument and controlledthrough the oscillator. The instruments shown in FIGS. 2 and 3 areparticularly adapted for use on flat and smooth glass, like plate orwindow glass, having a thickness up to A or /3 of an inch thick, and onrough surfaced glass, like figured or rough cast glass, having athickness up to A of an inch. As shown in FIG. 1, a scratch line 18 isformed on one or both plane surfaces of a sheet of glass. The vibratorshown in either FIG. 2 or 3 can beheld during operation by a suitablehandle mounted on the top of the cylinder and the sharp vibrating pointcan be directed along the scratch lines to cause the glass to form aclean break. The use of the above apparatus becomes even more im erativewhere the scratch line is in the form of a circle or a complicatedpattern or where the surface of the sheet is rough so that the scratchis discontinuous and consequently the Zone of least resistance obtainedin the glass is discontinuous.

It has been found that the use of percussion-vibration instruments ofthe type described above to cause breakage of sheets of glass having athickness in excess of /2 of an inch is unsatisfactory because suchinstruments have a tendency to create, in the thickness of the glass,local fractures which mar the final cut. in addition, the noise of suchpercussion-vibration instruments becomes more and more obnoxious as thefrequency and intensity of tare vibration increases. For sheets of glasshaving a thickness in excess of /2 of an inch, it has been foundnecessary to use instruments which create inaudible vi rations calledultrasonic vibrations which can be appncd the surface of the glass andwhich, because of their high frequency and intensity, create in the massof the glass itself vibrations of such intensity that the glass willbreak easily along the scratch lines formed on one or both surfaces. Inthose cases where the scratch cs are located on both surfaces, thescratch on the first surface is located in a plane perpendicular to saidsurface and passing through the scratch made on the second surface. Asuitable instrument for accomplishing this result is a transducer asshown in FIG. 4 wherein a stainless steel casing encloses a bar ofbarium titanate 21 or other suitable material which expands under theinfluence of an electrical current and contracts when the electricalcurrent is cut off. An electrical conducting wire 22 is spirally woundabout the bar 21. In the disclosed embodiment, the casing 2% is about 2inches wide, 1 inch deep and 2 or 3 feet long. It is to be understood,however, that these dimensions can be varied without departing from theprinciples of ths invention. The upper surface of casing is studded w ha plurality of spaced apart protrusions 23 and upon which the scratchline on a sheet is held in aligned contact for breaking the glass. Theends of wire 22 are electrically connected to an oscillator 24 which inturn is electrically connected to a source, not shown. The protrusions23 may be positioned in a straight line as shown or in any patterncorresponding to the desired shape of the area to be cut. The disclosedtrans-d cer produces vibrations in the order of 16,000 to 160,000vibrations per second with the frequency and in ensity of the vibrationsbeing selectively controlled by the output of the oscillator.

FIG. shows a modification of the instrument of FIG. 4 wherein twotransducers having the same construction and operation as shown in FIG.4 are placed on opposite sides of the sheet, the protrusions on eachbeing in alignment with a scratch surface on either side of the sheet.It has been found that glass having a thickness up to /12 of an inch canbe easily and readily cut by resting the sheet of glass on thetransducer shown in FIG. 4 so that the scratch line is in alignment withthe protrusions 23 on the top surface of the transducer. By causing thetransducer to produce at least 16,060 vibrations per second, there iscreated in said glass a vibrating condition of such magnitude that theglass will break, either by itself, or under a slight pressure on thesurface of the glass adjacent the scratch lines and form a neat cut. Thefrequency and intensity of the vibrations can be controlled through awide range to accommodate various thicknesses and types of glass. Whilethe length of the transducer is disclosed as 2 or 3 feet, it isunderstood that the transducer can be moved along the scratch line of amuch longer sheet as many times as necessary in order to cut the entirelength of the scratch line. In addition, the breaking of the glass sheetis greatly facilitated if scratch lines are formed on opposite surfacesof the glass in the manner previously described. For glass having athickness greater than /2 of an inch, the modified transducer as shownin FIG. 5 is used and the vibrations are either applied simultaneouslyor in sequence to the scratch lines on each surface.

FIG. 6 shows a further modification of a transducer structure whereineither one or two of the transducers shown in FIG. 4 are located in atank 25 which is filled with water or other suitable liquid. It has beenfound that in breaking sheets of glass having very great thicknesses,for example several inches, a more perfect contact is obtained betweenthe vibrating liquid and the glass to be broken than is the case whenthe contact is merely between the solid vibrator and the glass. In thisembodiment, either one transducer located below the sheet of glass or atransducer below and another above the sheet of glass may be used in thesame manner as they are used outside the tank of liquid.

This invention is also applicable to cutting glass which is in a cubicalor elongated cubical form so that it becomes necessary to make scratchlines not only on the upper and lower surfaces but also on the lateralsurfaces or" the blocks. For such shapes of glass, transducers as shownin FIG. 4 having appropriate lengths are placed adjacent the scratchlines on each surface may be successively subjected to the vibrations ofthe transducer to complete the breaking thereof. Furthermore, thetransducers may be operated in a fluid, as shown in FIG. 6, for extrathick glass.

While the present invention is herein illustrated and described inrelation to the cutting of glass sheets, it is to be understood that itis equally applicable to other forms and shapes of glass. Additionally,while the instruments creating the vibrations have been disclosed inrather specific detail as the types of percussion-vibrators and transducers, it is to be understood that other instruments which produce thedesired frequency and intensity of vibrations may be used, withoutdeparting from the spirit and scope of this invention.

This application is a division of my application Serial No. 793,417,filed February 16, 1959, now Patent No. 3,116,862.

What is claimed is:

1. Apparatus for applying vibration to a surface which comprises acontact adapted to engage the surface, a cylinder attached thereto, afree piston in the cylinder, means to vibrate the piston in thecylinder, and means to transmit the vibrations to the contact.

2. An apparatus for cutting glass having a scratch line on at least oneof its surfaces to define the cutting path, comprising vibrating meansto support said glass and to transmit to the lower surface of said glassand to said scratch line impact vibrations of high frequency andintensity, and a second vibrating means to contact and to transmit tothe upper surface of the glass and to said scratch line impactvibrations of high frequency and intensity, whcreby said glass is causedto be cut.

3. An apparatus for cutting glass having a scratch line on at least oneof its surfaces to define the cutting path, comprising a vibrating meansto support said glass and to transmit to the lower surface of said glassand to said scratch line impact vibrations of high frequency andintensity, and means to interpose a layer of liquid between the saidvibrating means and the lower surface of said glass during the cutting.

4. A glass breaker adapted to break glass along the line of a scoreconsisting in its essential elements of an elongated transducer, acasing therefor, said casing having a line of points adapted to enterinto and follow the line of the score, and means to supply current tothe transducer.

5. Apparatus for breaking glass along the line of a score including atank adapted to hold a liquid, a transducer mounted in the tank belowthe liquid level, a line of points mounted on the transducer so as to bevibrated thereby against the face of the glass along the line of thescore, and means to supply the transducer with oscillating current.

6. Apparatus for breaking glass along the line of a score whichcomprises a cylinder, an electromagnet therein, an external pointattached thereto adapted to enter the line of the score, a verticallymovable weight in the cylinder, and means to turn the magnet on and offrapidly whereby to generate impact vibrations of high frequency at thepoint by the rising and falling of the weight.

7. Apparatus for breaking glass along the line of the score whichcomprises a cylinder, at free weight Within the cylinder, pneumaticmeans to raise and lower the weight rapidly in the cylinder whereby togenerate the impact vibrations of high frequency and intensity, and apoint attached to the cylinder which is adapted to act upon the score.

8. Apparatus for severing glass along the line of a score comprising acasing having a multiplicity of aligned points adapted to fit the lineof the score, and means within the casing to generate vibrations of highfrequency and intensity in the points toward the score line.

9. Apparatus for severing glass along the line of a score whichcomprises an elongated casing having a row of points adapted to fit theline of the score, transducer means Within the casing to generatevibrations of high frequency and intensity in the points toward thescore line, and means to supply power to the said vibrations-producing 5means.

References Cited in the file of this patent UNITED STATES PATENTS 102,292,555 Wesch Aug. 11, 1942 2,337,569 Pietschack Dec. 28, 19432,982,456 Hsu et al. May 2, 1961 3,029,766 Jones Apr. 17, 1962 3,116,862De Gorter Jan. 7, 1964

1. APPARATUS FOR APPLYING VIBRATION TO A SURFACE WHICH COMPRISES ACONTACT ADAPTED TO ENGAGE THE SURFACE, A CYLIN-